Sadly, my otherwise very enjoyable experiance of Flightsim has been thwarted as increasingly I am receiving the dreaded the OOM message. I have trawled through previous postings relating to this subject and have come to the conclusion that I have to revert from XP(32) to a 64bit application. I have two questions: 1. Purchasing a 64bit application, would it be recommended to uninstall everything relating to Flightsim and basically start again with a blank canvas. I have to say I am bit daunted by this as it has taken years with numerous add-ons to get FS9 where it is today and 2. Would it better to stick with XP64 or make the jump to Windows 7? Ideally, someone will say there is an Windows XP disk that reverts my 32 bit application to a 64 bit application, but some how I think I am being too hopeful. Many thanks Tristan.

You should first try this tweak: http://www.fsdeveloper.com/wiki/index.php?title=OOM_ErrorOnly if it fails, start thinking about 64 bit Windows.

You should first try this tweak: http://www.fsdeveloper.com/wiki/index.php?title=OOM_ErrorOnly if it fails, start thinking about 64 bit Windows.

Well I will certainly try this. Thank you. However I thought the only solution was to revert to a 64bit O/S. Which was the main thrust of my post.

I would suggest you get windows 7 and do a fresh install. Daunting i know, but I did this in December and it was not that difficult. Just make backups of your addon scenery/ai aircraft repaints/user aircraft repaints and anything else you have added/edited in FS9 . Most of these can be just copied over once you have done an install, although paywawre and complicated scenery will be better if you install new. Flightsimming with FS9 is so much better on my new computer/win7 installation.You have obviously looked into the OOM errors, but in my experience they are caused by a faulty scenery, not a problem with physical memory or the operating system.ps. FS9 won't run as a 64 bit program on Win7, it can't. It will run quite happily as a 32 bit application. Just make sure you install outside of the default "program files" folder, and turn UAC off.

Maybe my post in 2008 would help? I always managed to clear OoM errors by removing the 'culprit' bgl file - though it can take some time and effort to find it on occasion!http://forums1.avsim.net/index.php?showtop...;hl=martinlest2Martin

Well I will certainly try this. Thank you. However I thought the only solution was to revert to a 64bit O/S. Which was the main thrust of my post.

Good gracious no. That is the last thing to do! You can patch the fs9.exe file to resolve the issue. See also here:http://www.adventure-unlimited.org/faultfinding.php#oomJohn

Good gracious no. That is the last thing to do! You can patch the fs9.exe file to resolve the issue. See also here:http://www.adventure-unlimited.org/faultfinding.php#oomJohn

Some of the detail in the page you linked to is incorrect. Patching the fs9 executable does nothing by itself--the OS must also be configured to permit allocation of >2GB of memory address space for an application. That can be done with the /3GB switch and a fine-tuned USERVA setting, which might provide relief for someone right on the ragged edge (and which can also make a 32-bit windows system unstable or even unbootable, depending on the PC configuration).The best long-term solution for OOM errors, especially as add-ons continue to get even larger and more complex, is a 64-bit operating system and at least 4 GB of system RAM. For FS9, you do need to patch the fs9.exe file to set the LARGEADDRESSAWARE flag in order to take advantage of the 64-bit OS' ability to allocate up to 4GB for a 32-bit app like FS9/FSX. SP2 for FSX already includes the necessary changes.RegardsBob ScottColonel, USAF (ret)ATP IMEL Gulfstream II-III-IV-VColorado Springs, CO

Maybe my post in 2008 would help? I always managed to clear OoM errors by removing the 'culprit' bgl file - though it can take some time and effort to find it on occasion!http://forums1.avsim.net/index.php?showtop...;hl=martinlest2Martin

^This is 100% correct. OOMs are not something that we have to live with. I've flown FS9 since the day it came out in many Windows versions. I've never, ever had an error that I couldn't eventually blame on 3rd party software. Go into fs9 and disable every 3rd party add-on scenery. I bet your crash goes away. The tricky part is finding the culprit.FS9 does not need a 64 bit OS to be stable (although there's nothing wrong with it).

True, wayward BGLS can cause OOM errors (leaks). And in your case I wouldn't resort to a format and fresh install of a 64bit OS just yet (try the LAA tweak as posted). I also noted running Ultimate Terrain is a memory hog and is behind many OOM errors when combined with addon scenery and a complex airliner (for example flying into KBOS or KJFK in the PMDG 747)For the future if you like to run add on scenery and airplanes and would like to never worry about OOM errors again go with a 64bit OS on your next format. NOTHING stinks more than 4-5 hours devoted to a flight only to OOM as you start heading down.I love my freeware/payware addon's and have many installed. Since I switched to 64bit OS I have not had an OOM error and I do not worry about memory leaks.I have said it before I will say it again, a 64bit OS is the best addon I have for FS9.

I would also recommend, just in case you don't have it, the little programme AutoSave - very simple and it will automatically save your flights at intervals you decide (e.g. every 5 minutes). All default a/c and most payware a/c (though not quite all) will load up again exactly as you left them before the OoM crash, including all cockpit instruments as they were (e.g. PMDG). It takes a little bit of the pain out of an OoM crash as you are about to land after a 5 hour flight!Available here, for instance, for FS2002/FS2004:http://www.schiratti.com/dowson.htmlOr the file "fsxsave105.zip" on AVSIM for FSXMartin

Some of the detail in the page you linked to is incorrect. Patching the fs9 executable does nothing by itself--the OS must also be configured to permit allocation of >2GB of memory address space for an application. That can be done with the /3GB switch and a fine-tuned USERVA setting, which might provide relief for someone right on the ragged edge (and which can also make a 32-bit windows system unstable or even unbootable, depending on the PC configuration).

That is indeed one of the possibilities discussed there, I'm not sure how that makes it "incorrect".John

Hacking your fs9.exe to use more memory is like dumping a truckload of sponges into your basement during a flood. Don't accept the leak, fix it.

Just to add my twopenny worth re. hacking the fs.exe file and the /3gb switch - I tried this in 2008 (before posting my thread re. dealing with the problem). It cured the OoM errors but also made scenery loading so slow that I was flying most of the time with very blurred ground textures that just never came into focus. Many people (though by no means all) have found there's a trade-off with hacking the files. I went back to the original files (and nice crisp textures straight away) and,as I have said, dealt with OoMs on a case=by-case basis. I have never not been able to fix one by locating and removing one or two bgl files (almost always landclass files)..Martin

Some of you folks are speaking as though these are equivalent causes. They are not.OOM's can and do result from multiple causes, only one of which is a "memory leak" caused by bad and/or missing scenery .bgl files, texture files, etc.The /3GB + userva reallocation procedure is meant to address only the case which results from having no remaining 1MB contiguous blocks of address space available. That is all.

And it's not so much a hack but a way around the 32bit OS limit. In fact the FSX.exe was patched with the LAA fix by ACES as a result of the many OOM errors people were getting with FSX.Phil Taylor explains it all here>>>http://blogs.msdn.com/ptaylor/archive/2007...ress-space.aspxIt's not a "leaky basement" it is a limit with 32bit OS (of course it can be a memory leak with a wayward BGL or a landcalss file along with a texture folder) but this is not always the case. Try loading many HQ images in Paint Shop Pro and you will also get an OOM error once you hit your 2GB limit with a 32bit OS. With a 64bit OS and a LAA patched exe you will not get an OOM error.....